3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
15 select X86_DEV_DMA_OPS
20 select HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PCSPKR_PLATFORM
25 select HAVE_PERF_EVENTS
27 select HAVE_IOREMAP_PROT
30 select HAVE_MEMBLOCK_NODE_MAP
31 select ARCH_DISCARD_MEMBLOCK
32 select ARCH_WANT_OPTIONAL_GPIOLIB
33 select ARCH_WANT_FRAME_POINTERS
35 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
36 select HAVE_KRETPROBES
38 select HAVE_FTRACE_MCOUNT_RECORD
39 select HAVE_C_RECORDMCOUNT
40 select HAVE_DYNAMIC_FTRACE
41 select HAVE_FUNCTION_TRACER
42 select HAVE_FUNCTION_GRAPH_TRACER
43 select HAVE_FUNCTION_GRAPH_FP_TEST
44 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
45 select HAVE_SYSCALL_TRACEPOINTS
48 select HAVE_ARCH_TRACEHOOK
49 select HAVE_GENERIC_DMA_COHERENT if X86_32
50 select HAVE_EFFICIENT_UNALIGNED_ACCESS
51 select USER_STACKTRACE_SUPPORT
52 select HAVE_REGS_AND_STACK_ACCESS_API
53 select HAVE_DMA_API_DEBUG
54 select HAVE_KERNEL_GZIP
55 select HAVE_KERNEL_BZIP2
56 select HAVE_KERNEL_LZMA
58 select HAVE_KERNEL_LZO
59 select HAVE_HW_BREAKPOINT
60 select HAVE_MIXED_BREAKPOINTS_REGS
62 select HAVE_PERF_EVENTS_NMI
64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
65 select HAVE_CMPXCHG_LOCAL if !M386
66 select HAVE_CMPXCHG_DOUBLE
67 select HAVE_ARCH_KMEMCHECK
68 select HAVE_USER_RETURN_NOTIFIER
69 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
70 select HAVE_ARCH_JUMP_LABEL
71 select HAVE_TEXT_POKE_SMP
72 select HAVE_GENERIC_HARDIRQS
73 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
75 select GENERIC_FIND_FIRST_BIT
76 select GENERIC_IRQ_PROBE
77 select GENERIC_PENDING_IRQ if SMP
78 select GENERIC_IRQ_SHOW
79 select GENERIC_CLOCKEVENTS_MIN_ADJUST
80 select IRQ_FORCED_THREADING
81 select USE_GENERIC_SMP_HELPERS if SMP
82 select HAVE_BPF_JIT if X86_64
84 select ARCH_HAVE_NMI_SAFE_CMPXCHG
86 select DCACHE_WORD_ACCESS
87 select GENERIC_SMP_IDLE_THREAD
88 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
89 select HAVE_ARCH_SECCOMP_FILTER
90 select BUILDTIME_EXTABLE_SORT
91 select GENERIC_CMOS_UPDATE
92 select CLOCKSOURCE_WATCHDOG
93 select GENERIC_CLOCKEVENTS
94 select ARCH_CLOCKSOURCE_DATA if X86_64
95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
96 select GENERIC_TIME_VSYSCALL if X86_64
97 select KTIME_SCALAR if X86_32
98 select GENERIC_STRNCPY_FROM_USER
99 select GENERIC_STRNLEN_USER
101 config INSTRUCTION_DECODER
102 def_bool (KPROBES || PERF_EVENTS || UPROBES)
106 default "elf32-i386" if X86_32
107 default "elf64-x86-64" if X86_64
109 config ARCH_DEFCONFIG
111 default "arch/x86/configs/i386_defconfig" if X86_32
112 default "arch/x86/configs/x86_64_defconfig" if X86_64
114 config LOCKDEP_SUPPORT
117 config STACKTRACE_SUPPORT
120 config HAVE_LATENCYTOP_SUPPORT
129 config NEED_DMA_MAP_STATE
130 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
132 config NEED_SG_DMA_LENGTH
135 config GENERIC_ISA_DMA
141 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
143 config GENERIC_BUG_RELATIVE_POINTERS
146 config GENERIC_HWEIGHT
152 config ARCH_MAY_HAVE_PC_FDC
155 config RWSEM_GENERIC_SPINLOCK
158 config RWSEM_XCHGADD_ALGORITHM
161 config GENERIC_CALIBRATE_DELAY
164 config ARCH_HAS_CPU_RELAX
167 config ARCH_HAS_DEFAULT_IDLE
170 config ARCH_HAS_CACHE_LINE_SIZE
173 config ARCH_HAS_CPU_AUTOPROBE
176 config HAVE_SETUP_PER_CPU_AREA
179 config NEED_PER_CPU_EMBED_FIRST_CHUNK
182 config NEED_PER_CPU_PAGE_FIRST_CHUNK
185 config ARCH_HIBERNATION_POSSIBLE
188 config ARCH_SUSPEND_POSSIBLE
199 config ARCH_SUPPORTS_OPTIMIZED_INLINING
202 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
205 config HAVE_INTEL_TXT
207 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
211 depends on X86_32 && SMP
215 depends on X86_64 && SMP
221 config X86_32_LAZY_GS
223 depends on X86_32 && !CC_STACKPROTECTOR
225 config ARCH_HWEIGHT_CFLAGS
227 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
228 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
230 config ARCH_CPU_PROBE_RELEASE
232 depends on HOTPLUG_CPU
234 config ARCH_SUPPORTS_UPROBES
237 source "init/Kconfig"
238 source "kernel/Kconfig.freezer"
240 menu "Processor type and features"
243 bool "DMA memory allocation support" if EXPERT
246 DMA memory allocation support allows devices with less than 32-bit
247 addressing to allocate within the first 16MB of address space.
248 Disable if no such devices will be used.
253 bool "Symmetric multi-processing support"
255 This enables support for systems with more than one CPU. If you have
256 a system with only one CPU, like most personal computers, say N. If
257 you have a system with more than one CPU, say Y.
259 If you say N here, the kernel will run on single and multiprocessor
260 machines, but will use only one CPU of a multiprocessor machine. If
261 you say Y here, the kernel will run on many, but not all,
262 singleprocessor machines. On a singleprocessor machine, the kernel
263 will run faster if you say N here.
265 Note that if you say Y here and choose architecture "586" or
266 "Pentium" under "Processor family", the kernel will not work on 486
267 architectures. Similarly, multiprocessor kernels for the "PPro"
268 architecture may not work on all Pentium based boards.
270 People using multiprocessor machines who say Y here should also say
271 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
272 Management" code will be disabled if you say Y here.
274 See also <file:Documentation/x86/i386/IO-APIC.txt>,
275 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
276 <http://www.tldp.org/docs.html#howto>.
278 If you don't know what to do here, say N.
281 bool "Support x2apic"
282 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
284 This enables x2apic support on CPUs that have this feature.
286 This allows 32-bit apic IDs (so it can support very large systems),
287 and accesses the local apic via MSRs not via mmio.
289 If you don't know what to do here, say N.
292 bool "Enable MPS table" if ACPI
294 depends on X86_LOCAL_APIC
296 For old smp systems that do not have proper acpi support. Newer systems
297 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
300 bool "Support for big SMP systems with more than 8 CPUs"
301 depends on X86_32 && SMP
303 This option is needed for the systems that have more than 8 CPUs
306 config X86_EXTENDED_PLATFORM
307 bool "Support for extended (non-PC) x86 platforms"
310 If you disable this option then the kernel will only support
311 standard PC platforms. (which covers the vast majority of
314 If you enable this option then you'll be able to select support
315 for the following (non-PC) 32 bit x86 platforms:
319 SGI 320/540 (Visual Workstation)
320 STA2X11-based (e.g. Northville)
321 Summit/EXA (IBM x440)
322 Unisys ES7000 IA32 series
323 Moorestown MID devices
325 If you have one of these systems, or if you want to build a
326 generic distribution kernel, say Y here - otherwise say N.
330 config X86_EXTENDED_PLATFORM
331 bool "Support for extended (non-PC) x86 platforms"
334 If you disable this option then the kernel will only support
335 standard PC platforms. (which covers the vast majority of
338 If you enable this option then you'll be able to select support
339 for the following (non-PC) 64 bit x86 platforms:
344 If you have one of these systems, or if you want to build a
345 generic distribution kernel, say Y here - otherwise say N.
347 # This is an alphabetically sorted list of 64 bit extended platforms
348 # Please maintain the alphabetic order if and when there are additions
350 bool "Numascale NumaChip"
352 depends on X86_EXTENDED_PLATFORM
355 depends on X86_X2APIC
357 Adds support for Numascale NumaChip large-SMP systems. Needed to
358 enable more than ~168 cores.
359 If you don't have one of these, you should say N here.
363 select PARAVIRT_GUEST
365 depends on X86_64 && PCI
366 depends on X86_EXTENDED_PLATFORM
369 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
370 supposed to run on these EM64T-based machines. Only choose this option
371 if you have one of these machines.
374 bool "SGI Ultraviolet"
376 depends on X86_EXTENDED_PLATFORM
378 depends on X86_X2APIC
380 This option is needed in order to support SGI Ultraviolet systems.
381 If you don't have one of these, you should say N here.
383 # Following is an alphabetically sorted list of 32 bit extended platforms
384 # Please maintain the alphabetic order if and when there are additions
387 bool "CE4100 TV platform"
389 depends on PCI_GODIRECT
391 depends on X86_EXTENDED_PLATFORM
392 select X86_REBOOTFIXUPS
394 select OF_EARLY_FLATTREE
397 Select for the Intel CE media processor (CE4100) SOC.
398 This option compiles in support for the CE4100 SOC for settop
399 boxes and media devices.
401 config X86_WANT_INTEL_MID
402 bool "Intel MID platform support"
404 depends on X86_EXTENDED_PLATFORM
406 Select to build a kernel capable of supporting Intel MID platform
407 systems which do not have the PCI legacy interfaces (Moorestown,
408 Medfield). If you are building for a PC class system say N here.
410 if X86_WANT_INTEL_MID
416 bool "Medfield MID platform"
419 depends on X86_IO_APIC
427 select X86_PLATFORM_DEVICES
428 select MFD_INTEL_MSIC
430 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
431 Internet Device(MID) platform.
432 Unlike standard x86 PCs, Medfield does not have many legacy devices
433 nor standard legacy replacement devices/features. e.g. Medfield does
434 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
439 bool "RDC R-321x SoC"
441 depends on X86_EXTENDED_PLATFORM
443 select X86_REBOOTFIXUPS
445 This option is needed for RDC R-321x system-on-chip, also known
447 If you don't have one of these chips, you should say N here.
449 config X86_32_NON_STANDARD
450 bool "Support non-standard 32-bit SMP architectures"
451 depends on X86_32 && SMP
452 depends on X86_EXTENDED_PLATFORM
454 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
455 STA2X11, default subarchitectures. It is intended for a generic
456 binary kernel. If you select them all, kernel will probe it
457 one by one and will fallback to default.
459 # Alphabetically sorted list of Non standard 32 bit platforms
462 bool "NUMAQ (IBM/Sequent)"
463 depends on X86_32_NON_STANDARD
468 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
469 NUMA multiquad box. This changes the way that processors are
470 bootstrapped, and uses Clustered Logical APIC addressing mode instead
471 of Flat Logical. You will need a new lynxer.elf file to flash your
472 firmware with - send email to <Martin.Bligh@us.ibm.com>.
474 config X86_SUPPORTS_MEMORY_FAILURE
476 # MCE code calls memory_failure():
478 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
479 depends on !X86_NUMAQ
480 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
481 depends on X86_64 || !SPARSEMEM
482 select ARCH_SUPPORTS_MEMORY_FAILURE
485 bool "SGI 320/540 (Visual Workstation)"
486 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
487 depends on X86_32_NON_STANDARD
489 The SGI Visual Workstation series is an IA32-based workstation
490 based on SGI systems chips with some legacy PC hardware attached.
492 Say Y here to create a kernel to run on the SGI 320 or 540.
494 A kernel compiled for the Visual Workstation will run on general
495 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
498 bool "STA2X11 Companion Chip Support"
499 depends on X86_32_NON_STANDARD && PCI
500 select X86_DEV_DMA_OPS
504 select ARCH_REQUIRE_GPIOLIB
507 This adds support for boards based on the STA2X11 IO-Hub,
508 a.k.a. "ConneXt". The chip is used in place of the standard
509 PC chipset, so all "standard" peripherals are missing. If this
510 option is selected the kernel will still be able to boot on
511 standard PC machines.
514 bool "Summit/EXA (IBM x440)"
515 depends on X86_32_NON_STANDARD
517 This option is needed for IBM systems that use the Summit/EXA chipset.
518 In particular, it is needed for the x440.
521 bool "Unisys ES7000 IA32 series"
522 depends on X86_32_NON_STANDARD && X86_BIGSMP
524 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
525 supposed to run on an IA32-based Unisys ES7000 system.
528 tristate "Eurobraille/Iris poweroff module"
531 The Iris machines from EuroBraille do not have APM or ACPI support
532 to shut themselves down properly. A special I/O sequence is
533 needed to do so, which is what this module does at
536 This is only for Iris machines from EuroBraille.
540 config SCHED_OMIT_FRAME_POINTER
542 prompt "Single-depth WCHAN output"
545 Calculate simpler /proc/<PID>/wchan values. If this option
546 is disabled then wchan values will recurse back to the
547 caller function. This provides more accurate wchan values,
548 at the expense of slightly more scheduling overhead.
550 If in doubt, say "Y".
552 menuconfig PARAVIRT_GUEST
553 bool "Paravirtualized guest support"
555 Say Y here to get to see options related to running Linux under
556 various hypervisors. This option alone does not add any kernel code.
558 If you say N, all options in this submenu will be skipped and disabled.
562 config PARAVIRT_TIME_ACCOUNTING
563 bool "Paravirtual steal time accounting"
567 Select this option to enable fine granularity task steal time
568 accounting. Time spent executing other tasks in parallel with
569 the current vCPU is discounted from the vCPU power. To account for
570 that, there can be a small performance impact.
572 If in doubt, say N here.
574 source "arch/x86/xen/Kconfig"
577 bool "KVM Guest support (including kvmclock)"
580 select PARAVIRT_CLOCK
581 default y if PARAVIRT_GUEST
583 This option enables various optimizations for running under the KVM
584 hypervisor. It includes a paravirtualized clock, so that instead
585 of relying on a PIT (or probably other) emulation by the
586 underlying device model, the host provides the guest with
587 timing infrastructure such as time of day, and system time
589 source "arch/x86/lguest/Kconfig"
592 bool "Enable paravirtualization code"
594 This changes the kernel so it can modify itself when it is run
595 under a hypervisor, potentially improving performance significantly
596 over full virtualization. However, when run without a hypervisor
597 the kernel is theoretically slower and slightly larger.
599 config PARAVIRT_SPINLOCKS
600 bool "Paravirtualization layer for spinlocks"
601 depends on PARAVIRT && SMP && EXPERIMENTAL
603 Paravirtualized spinlocks allow a pvops backend to replace the
604 spinlock implementation with something virtualization-friendly
605 (for example, block the virtual CPU rather than spinning).
607 Unfortunately the downside is an up to 5% performance hit on
608 native kernels, with various workloads.
610 If you are unsure how to answer this question, answer N.
612 config PARAVIRT_CLOCK
617 config PARAVIRT_DEBUG
618 bool "paravirt-ops debugging"
619 depends on PARAVIRT && DEBUG_KERNEL
621 Enable to debug paravirt_ops internals. Specifically, BUG if
622 a paravirt_op is missing when it is called.
630 This option adds a kernel parameter 'memtest', which allows memtest
632 memtest=0, mean disabled; -- default
633 memtest=1, mean do 1 test pattern;
635 memtest=4, mean do 4 test patterns.
636 If you are unsure how to answer this question, answer N.
638 config X86_SUMMIT_NUMA
640 depends on X86_32 && NUMA && X86_32_NON_STANDARD
642 config X86_CYCLONE_TIMER
644 depends on X86_SUMMIT
646 source "arch/x86/Kconfig.cpu"
650 prompt "HPET Timer Support" if X86_32
652 Use the IA-PC HPET (High Precision Event Timer) to manage
653 time in preference to the PIT and RTC, if a HPET is
655 HPET is the next generation timer replacing legacy 8254s.
656 The HPET provides a stable time base on SMP
657 systems, unlike the TSC, but it is more expensive to access,
658 as it is off-chip. You can find the HPET spec at
659 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
661 You can safely choose Y here. However, HPET will only be
662 activated if the platform and the BIOS support this feature.
663 Otherwise the 8254 will be used for timing services.
665 Choose N to continue using the legacy 8254 timer.
667 config HPET_EMULATE_RTC
669 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
672 def_bool y if X86_INTEL_MID
673 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
675 depends on X86_INTEL_MID && SFI
677 APB timer is the replacement for 8254, HPET on X86 MID platforms.
678 The APBT provides a stable time base on SMP
679 systems, unlike the TSC, but it is more expensive to access,
680 as it is off-chip. APB timers are always running regardless of CPU
681 C states, they are used as per CPU clockevent device when possible.
683 # Mark as expert because too many people got it wrong.
684 # The code disables itself when not needed.
687 bool "Enable DMI scanning" if EXPERT
689 Enabled scanning of DMI to identify machine quirks. Say Y
690 here unless you have verified that your setup is not
691 affected by entries in the DMI blacklist. Required by PNP
695 bool "GART IOMMU support" if EXPERT
698 depends on X86_64 && PCI && AMD_NB
700 Support for full DMA access of devices with 32bit memory access only
701 on systems with more than 3GB. This is usually needed for USB,
702 sound, many IDE/SATA chipsets and some other devices.
703 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
704 based hardware IOMMU and a software bounce buffer based IOMMU used
705 on Intel systems and as fallback.
706 The code is only active when needed (enough memory and limited
707 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
711 bool "IBM Calgary IOMMU support"
713 depends on X86_64 && PCI && EXPERIMENTAL
715 Support for hardware IOMMUs in IBM's xSeries x366 and x460
716 systems. Needed to run systems with more than 3GB of memory
717 properly with 32-bit PCI devices that do not support DAC
718 (Double Address Cycle). Calgary also supports bus level
719 isolation, where all DMAs pass through the IOMMU. This
720 prevents them from going anywhere except their intended
721 destination. This catches hard-to-find kernel bugs and
722 mis-behaving drivers and devices that do not use the DMA-API
723 properly to set up their DMA buffers. The IOMMU can be
724 turned off at boot time with the iommu=off parameter.
725 Normally the kernel will make the right choice by itself.
728 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
730 prompt "Should Calgary be enabled by default?"
731 depends on CALGARY_IOMMU
733 Should Calgary be enabled by default? if you choose 'y', Calgary
734 will be used (if it exists). If you choose 'n', Calgary will not be
735 used even if it exists. If you choose 'n' and would like to use
736 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
739 # need this always selected by IOMMU for the VIA workaround
743 Support for software bounce buffers used on x86-64 systems
744 which don't have a hardware IOMMU (e.g. the current generation
745 of Intel's x86-64 CPUs). Using this PCI devices which can only
746 access 32-bits of memory can be used on systems with more than
747 3 GB of memory. If unsure, say Y.
750 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
753 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
754 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
755 select CPUMASK_OFFSTACK
757 Enable maximum number of CPUS and NUMA Nodes for this architecture.
761 int "Maximum number of CPUs" if SMP && !MAXSMP
762 range 2 8 if SMP && X86_32 && !X86_BIGSMP
763 range 2 512 if SMP && !MAXSMP
765 default "4096" if MAXSMP
766 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
769 This allows you to specify the maximum number of CPUs which this
770 kernel will support. The maximum supported value is 512 and the
771 minimum value which makes sense is 2.
773 This is purely to save memory - each supported CPU adds
774 approximately eight kilobytes to the kernel image.
777 bool "SMT (Hyperthreading) scheduler support"
780 SMT scheduler support improves the CPU scheduler's decision making
781 when dealing with Intel Pentium 4 chips with HyperThreading at a
782 cost of slightly increased overhead in some places. If unsure say
787 prompt "Multi-core scheduler support"
790 Multi-core scheduler support improves the CPU scheduler's decision
791 making when dealing with multi-core CPU chips at a cost of slightly
792 increased overhead in some places. If unsure say N here.
794 config IRQ_TIME_ACCOUNTING
795 bool "Fine granularity task level IRQ time accounting"
798 Select this option to enable fine granularity task irq time
799 accounting. This is done by reading a timestamp on each
800 transitions between softirq and hardirq state, so there can be a
801 small performance impact.
803 If in doubt, say N here.
805 source "kernel/Kconfig.preempt"
808 bool "Local APIC support on uniprocessors"
809 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
811 A local APIC (Advanced Programmable Interrupt Controller) is an
812 integrated interrupt controller in the CPU. If you have a single-CPU
813 system which has a processor with a local APIC, you can say Y here to
814 enable and use it. If you say Y here even though your machine doesn't
815 have a local APIC, then the kernel will still run with no slowdown at
816 all. The local APIC supports CPU-generated self-interrupts (timer,
817 performance counters), and the NMI watchdog which detects hard
821 bool "IO-APIC support on uniprocessors"
822 depends on X86_UP_APIC
824 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
825 SMP-capable replacement for PC-style interrupt controllers. Most
826 SMP systems and many recent uniprocessor systems have one.
828 If you have a single-CPU system with an IO-APIC, you can say Y here
829 to use it. If you say Y here even though your machine doesn't have
830 an IO-APIC, then the kernel will still run with no slowdown at all.
832 config X86_LOCAL_APIC
834 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
838 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
840 config X86_VISWS_APIC
842 depends on X86_32 && X86_VISWS
844 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
845 bool "Reroute for broken boot IRQs"
846 depends on X86_IO_APIC
848 This option enables a workaround that fixes a source of
849 spurious interrupts. This is recommended when threaded
850 interrupt handling is used on systems where the generation of
851 superfluous "boot interrupts" cannot be disabled.
853 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
854 entry in the chipset's IO-APIC is masked (as, e.g. the RT
855 kernel does during interrupt handling). On chipsets where this
856 boot IRQ generation cannot be disabled, this workaround keeps
857 the original IRQ line masked so that only the equivalent "boot
858 IRQ" is delivered to the CPUs. The workaround also tells the
859 kernel to set up the IRQ handler on the boot IRQ line. In this
860 way only one interrupt is delivered to the kernel. Otherwise
861 the spurious second interrupt may cause the kernel to bring
862 down (vital) interrupt lines.
864 Only affects "broken" chipsets. Interrupt sharing may be
865 increased on these systems.
868 bool "Machine Check / overheating reporting"
870 Machine Check support allows the processor to notify the
871 kernel if it detects a problem (e.g. overheating, data corruption).
872 The action the kernel takes depends on the severity of the problem,
873 ranging from warning messages to halting the machine.
877 prompt "Intel MCE features"
878 depends on X86_MCE && X86_LOCAL_APIC
880 Additional support for intel specific MCE features such as
885 prompt "AMD MCE features"
886 depends on X86_MCE && X86_LOCAL_APIC
888 Additional support for AMD specific MCE features such as
889 the DRAM Error Threshold.
891 config X86_ANCIENT_MCE
892 bool "Support for old Pentium 5 / WinChip machine checks"
893 depends on X86_32 && X86_MCE
895 Include support for machine check handling on old Pentium 5 or WinChip
896 systems. These typically need to be enabled explicitely on the command
899 config X86_MCE_THRESHOLD
900 depends on X86_MCE_AMD || X86_MCE_INTEL
903 config X86_MCE_INJECT
905 tristate "Machine check injector support"
907 Provide support for injecting machine checks for testing purposes.
908 If you don't know what a machine check is and you don't do kernel
909 QA it is safe to say n.
911 config X86_THERMAL_VECTOR
913 depends on X86_MCE_INTEL
916 bool "Enable VM86 support" if EXPERT
920 This option is required by programs like DOSEMU to run 16-bit legacy
921 code on X86 processors. It also may be needed by software like
922 XFree86 to initialize some video cards via BIOS. Disabling this
923 option saves about 6k.
926 tristate "Toshiba Laptop support"
929 This adds a driver to safely access the System Management Mode of
930 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
931 not work on models with a Phoenix BIOS. The System Management Mode
932 is used to set the BIOS and power saving options on Toshiba portables.
934 For information on utilities to make use of this driver see the
935 Toshiba Linux utilities web site at:
936 <http://www.buzzard.org.uk/toshiba/>.
938 Say Y if you intend to run this kernel on a Toshiba portable.
942 tristate "Dell laptop support"
945 This adds a driver to safely access the System Management Mode
946 of the CPU on the Dell Inspiron 8000. The System Management Mode
947 is used to read cpu temperature and cooling fan status and to
948 control the fans on the I8K portables.
950 This driver has been tested only on the Inspiron 8000 but it may
951 also work with other Dell laptops. You can force loading on other
952 models by passing the parameter `force=1' to the module. Use at
955 For information on utilities to make use of this driver see the
956 I8K Linux utilities web site at:
957 <http://people.debian.org/~dz/i8k/>
959 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
962 config X86_REBOOTFIXUPS
963 bool "Enable X86 board specific fixups for reboot"
966 This enables chipset and/or board specific fixups to be done
967 in order to get reboot to work correctly. This is only needed on
968 some combinations of hardware and BIOS. The symptom, for which
969 this config is intended, is when reboot ends with a stalled/hung
972 Currently, the only fixup is for the Geode machines using
973 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
975 Say Y if you want to enable the fixup. Currently, it's safe to
976 enable this option even if you don't need it.
980 tristate "/dev/cpu/microcode - microcode support"
983 If you say Y here, you will be able to update the microcode on
984 certain Intel and AMD processors. The Intel support is for the
985 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
986 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
987 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
988 You will obviously need the actual microcode binary data itself
989 which is not shipped with the Linux kernel.
991 This option selects the general module only, you need to select
992 at least one vendor specific module as well.
994 To compile this driver as a module, choose M here: the
995 module will be called microcode.
997 config MICROCODE_INTEL
998 bool "Intel microcode patch loading support"
1003 This options enables microcode patch loading support for Intel
1006 For latest news and information on obtaining all the required
1007 Intel ingredients for this driver, check:
1008 <http://www.urbanmyth.org/microcode/>.
1010 config MICROCODE_AMD
1011 bool "AMD microcode patch loading support"
1012 depends on MICROCODE
1015 If you select this option, microcode patch loading support for AMD
1016 processors will be enabled.
1018 config MICROCODE_OLD_INTERFACE
1020 depends on MICROCODE
1023 tristate "/dev/cpu/*/msr - Model-specific register support"
1025 This device gives privileged processes access to the x86
1026 Model-Specific Registers (MSRs). It is a character device with
1027 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1028 MSR accesses are directed to a specific CPU on multi-processor
1032 tristate "/dev/cpu/*/cpuid - CPU information support"
1034 This device gives processes access to the x86 CPUID instruction to
1035 be executed on a specific processor. It is a character device
1036 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1040 prompt "High Memory Support"
1041 default HIGHMEM64G if X86_NUMAQ
1047 depends on !X86_NUMAQ
1049 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1050 However, the address space of 32-bit x86 processors is only 4
1051 Gigabytes large. That means that, if you have a large amount of
1052 physical memory, not all of it can be "permanently mapped" by the
1053 kernel. The physical memory that's not permanently mapped is called
1056 If you are compiling a kernel which will never run on a machine with
1057 more than 1 Gigabyte total physical RAM, answer "off" here (default
1058 choice and suitable for most users). This will result in a "3GB/1GB"
1059 split: 3GB are mapped so that each process sees a 3GB virtual memory
1060 space and the remaining part of the 4GB virtual memory space is used
1061 by the kernel to permanently map as much physical memory as
1064 If the machine has between 1 and 4 Gigabytes physical RAM, then
1067 If more than 4 Gigabytes is used then answer "64GB" here. This
1068 selection turns Intel PAE (Physical Address Extension) mode on.
1069 PAE implements 3-level paging on IA32 processors. PAE is fully
1070 supported by Linux, PAE mode is implemented on all recent Intel
1071 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1072 then the kernel will not boot on CPUs that don't support PAE!
1074 The actual amount of total physical memory will either be
1075 auto detected or can be forced by using a kernel command line option
1076 such as "mem=256M". (Try "man bootparam" or see the documentation of
1077 your boot loader (lilo or loadlin) about how to pass options to the
1078 kernel at boot time.)
1080 If unsure, say "off".
1084 depends on !X86_NUMAQ
1086 Select this if you have a 32-bit processor and between 1 and 4
1087 gigabytes of physical RAM.
1091 depends on !M386 && !M486
1094 Select this if you have a 32-bit processor and more than 4
1095 gigabytes of physical RAM.
1100 depends on EXPERIMENTAL
1101 prompt "Memory split" if EXPERT
1105 Select the desired split between kernel and user memory.
1107 If the address range available to the kernel is less than the
1108 physical memory installed, the remaining memory will be available
1109 as "high memory". Accessing high memory is a little more costly
1110 than low memory, as it needs to be mapped into the kernel first.
1111 Note that increasing the kernel address space limits the range
1112 available to user programs, making the address space there
1113 tighter. Selecting anything other than the default 3G/1G split
1114 will also likely make your kernel incompatible with binary-only
1117 If you are not absolutely sure what you are doing, leave this
1121 bool "3G/1G user/kernel split"
1122 config VMSPLIT_3G_OPT
1124 bool "3G/1G user/kernel split (for full 1G low memory)"
1126 bool "2G/2G user/kernel split"
1127 config VMSPLIT_2G_OPT
1129 bool "2G/2G user/kernel split (for full 2G low memory)"
1131 bool "1G/3G user/kernel split"
1136 default 0xB0000000 if VMSPLIT_3G_OPT
1137 default 0x80000000 if VMSPLIT_2G
1138 default 0x78000000 if VMSPLIT_2G_OPT
1139 default 0x40000000 if VMSPLIT_1G
1145 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1148 bool "PAE (Physical Address Extension) Support"
1149 depends on X86_32 && !HIGHMEM4G
1151 PAE is required for NX support, and furthermore enables
1152 larger swapspace support for non-overcommit purposes. It
1153 has the cost of more pagetable lookup overhead, and also
1154 consumes more pagetable space per process.
1156 config ARCH_PHYS_ADDR_T_64BIT
1157 def_bool X86_64 || X86_PAE
1159 config ARCH_DMA_ADDR_T_64BIT
1160 def_bool X86_64 || HIGHMEM64G
1162 config DIRECT_GBPAGES
1163 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1167 Allow the kernel linear mapping to use 1GB pages on CPUs that
1168 support it. This can improve the kernel's performance a tiny bit by
1169 reducing TLB pressure. If in doubt, say "Y".
1171 # Common NUMA Features
1173 bool "Numa Memory Allocation and Scheduler Support"
1175 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1176 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1178 Enable NUMA (Non Uniform Memory Access) support.
1180 The kernel will try to allocate memory used by a CPU on the
1181 local memory controller of the CPU and add some more
1182 NUMA awareness to the kernel.
1184 For 64-bit this is recommended if the system is Intel Core i7
1185 (or later), AMD Opteron, or EM64T NUMA.
1187 For 32-bit this is only needed on (rare) 32-bit-only platforms
1188 that support NUMA topologies, such as NUMAQ / Summit, or if you
1189 boot a 32-bit kernel on a 64-bit NUMA platform.
1191 Otherwise, you should say N.
1193 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1194 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1198 prompt "Old style AMD Opteron NUMA detection"
1199 depends on X86_64 && NUMA && PCI
1201 Enable AMD NUMA node topology detection. You should say Y here if
1202 you have a multi processor AMD system. This uses an old method to
1203 read the NUMA configuration directly from the builtin Northbridge
1204 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1205 which also takes priority if both are compiled in.
1207 config X86_64_ACPI_NUMA
1209 prompt "ACPI NUMA detection"
1210 depends on X86_64 && NUMA && ACPI && PCI
1213 Enable ACPI SRAT based node topology detection.
1215 # Some NUMA nodes have memory ranges that span
1216 # other nodes. Even though a pfn is valid and
1217 # between a node's start and end pfns, it may not
1218 # reside on that node. See memmap_init_zone()
1220 config NODES_SPAN_OTHER_NODES
1222 depends on X86_64_ACPI_NUMA
1225 bool "NUMA emulation"
1228 Enable NUMA emulation. A flat machine will be split
1229 into virtual nodes when booted with "numa=fake=N", where N is the
1230 number of nodes. This is only useful for debugging.
1233 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1235 default "10" if MAXSMP
1236 default "6" if X86_64
1237 default "4" if X86_NUMAQ
1239 depends on NEED_MULTIPLE_NODES
1241 Specify the maximum number of NUMA Nodes available on the target
1242 system. Increases memory reserved to accommodate various tables.
1244 config HAVE_ARCH_ALLOC_REMAP
1246 depends on X86_32 && NUMA
1248 config ARCH_HAVE_MEMORY_PRESENT
1250 depends on X86_32 && DISCONTIGMEM
1252 config NEED_NODE_MEMMAP_SIZE
1254 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1256 config ARCH_FLATMEM_ENABLE
1258 depends on X86_32 && !NUMA
1260 config ARCH_DISCONTIGMEM_ENABLE
1262 depends on NUMA && X86_32
1264 config ARCH_DISCONTIGMEM_DEFAULT
1266 depends on NUMA && X86_32
1268 config ARCH_SPARSEMEM_ENABLE
1270 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1271 select SPARSEMEM_STATIC if X86_32
1272 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1274 config ARCH_SPARSEMEM_DEFAULT
1278 config ARCH_SELECT_MEMORY_MODEL
1280 depends on ARCH_SPARSEMEM_ENABLE
1282 config ARCH_MEMORY_PROBE
1284 depends on MEMORY_HOTPLUG
1286 config ARCH_PROC_KCORE_TEXT
1288 depends on X86_64 && PROC_KCORE
1290 config ILLEGAL_POINTER_VALUE
1293 default 0xdead000000000000 if X86_64
1298 bool "Allocate 3rd-level pagetables from highmem"
1301 The VM uses one page table entry for each page of physical memory.
1302 For systems with a lot of RAM, this can be wasteful of precious
1303 low memory. Setting this option will put user-space page table
1304 entries in high memory.
1306 config X86_CHECK_BIOS_CORRUPTION
1307 bool "Check for low memory corruption"
1309 Periodically check for memory corruption in low memory, which
1310 is suspected to be caused by BIOS. Even when enabled in the
1311 configuration, it is disabled at runtime. Enable it by
1312 setting "memory_corruption_check=1" on the kernel command
1313 line. By default it scans the low 64k of memory every 60
1314 seconds; see the memory_corruption_check_size and
1315 memory_corruption_check_period parameters in
1316 Documentation/kernel-parameters.txt to adjust this.
1318 When enabled with the default parameters, this option has
1319 almost no overhead, as it reserves a relatively small amount
1320 of memory and scans it infrequently. It both detects corruption
1321 and prevents it from affecting the running system.
1323 It is, however, intended as a diagnostic tool; if repeatable
1324 BIOS-originated corruption always affects the same memory,
1325 you can use memmap= to prevent the kernel from using that
1328 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1329 bool "Set the default setting of memory_corruption_check"
1330 depends on X86_CHECK_BIOS_CORRUPTION
1333 Set whether the default state of memory_corruption_check is
1336 config X86_RESERVE_LOW
1337 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1341 Specify the amount of low memory to reserve for the BIOS.
1343 The first page contains BIOS data structures that the kernel
1344 must not use, so that page must always be reserved.
1346 By default we reserve the first 64K of physical RAM, as a
1347 number of BIOSes are known to corrupt that memory range
1348 during events such as suspend/resume or monitor cable
1349 insertion, so it must not be used by the kernel.
1351 You can set this to 4 if you are absolutely sure that you
1352 trust the BIOS to get all its memory reservations and usages
1353 right. If you know your BIOS have problems beyond the
1354 default 64K area, you can set this to 640 to avoid using the
1355 entire low memory range.
1357 If you have doubts about the BIOS (e.g. suspend/resume does
1358 not work or there's kernel crashes after certain hardware
1359 hotplug events) then you might want to enable
1360 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1361 typical corruption patterns.
1363 Leave this to the default value of 64 if you are unsure.
1365 config MATH_EMULATION
1367 prompt "Math emulation" if X86_32
1369 Linux can emulate a math coprocessor (used for floating point
1370 operations) if you don't have one. 486DX and Pentium processors have
1371 a math coprocessor built in, 486SX and 386 do not, unless you added
1372 a 487DX or 387, respectively. (The messages during boot time can
1373 give you some hints here ["man dmesg"].) Everyone needs either a
1374 coprocessor or this emulation.
1376 If you don't have a math coprocessor, you need to say Y here; if you
1377 say Y here even though you have a coprocessor, the coprocessor will
1378 be used nevertheless. (This behavior can be changed with the kernel
1379 command line option "no387", which comes handy if your coprocessor
1380 is broken. Try "man bootparam" or see the documentation of your boot
1381 loader (lilo or loadlin) about how to pass options to the kernel at
1382 boot time.) This means that it is a good idea to say Y here if you
1383 intend to use this kernel on different machines.
1385 More information about the internals of the Linux math coprocessor
1386 emulation can be found in <file:arch/x86/math-emu/README>.
1388 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1389 kernel, it won't hurt.
1393 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1395 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1396 the Memory Type Range Registers (MTRRs) may be used to control
1397 processor access to memory ranges. This is most useful if you have
1398 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1399 allows bus write transfers to be combined into a larger transfer
1400 before bursting over the PCI/AGP bus. This can increase performance
1401 of image write operations 2.5 times or more. Saying Y here creates a
1402 /proc/mtrr file which may be used to manipulate your processor's
1403 MTRRs. Typically the X server should use this.
1405 This code has a reasonably generic interface so that similar
1406 control registers on other processors can be easily supported
1409 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1410 Registers (ARRs) which provide a similar functionality to MTRRs. For
1411 these, the ARRs are used to emulate the MTRRs.
1412 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1413 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1414 write-combining. All of these processors are supported by this code
1415 and it makes sense to say Y here if you have one of them.
1417 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1418 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1419 can lead to all sorts of problems, so it's good to say Y here.
1421 You can safely say Y even if your machine doesn't have MTRRs, you'll
1422 just add about 9 KB to your kernel.
1424 See <file:Documentation/x86/mtrr.txt> for more information.
1426 config MTRR_SANITIZER
1428 prompt "MTRR cleanup support"
1431 Convert MTRR layout from continuous to discrete, so X drivers can
1432 add writeback entries.
1434 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1435 The largest mtrr entry size for a continuous block can be set with
1440 config MTRR_SANITIZER_ENABLE_DEFAULT
1441 int "MTRR cleanup enable value (0-1)"
1444 depends on MTRR_SANITIZER
1446 Enable mtrr cleanup default value
1448 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1449 int "MTRR cleanup spare reg num (0-7)"
1452 depends on MTRR_SANITIZER
1454 mtrr cleanup spare entries default, it can be changed via
1455 mtrr_spare_reg_nr=N on the kernel command line.
1459 prompt "x86 PAT support" if EXPERT
1462 Use PAT attributes to setup page level cache control.
1464 PATs are the modern equivalents of MTRRs and are much more
1465 flexible than MTRRs.
1467 Say N here if you see bootup problems (boot crash, boot hang,
1468 spontaneous reboots) or a non-working video driver.
1472 config ARCH_USES_PG_UNCACHED
1478 prompt "x86 architectural random number generator" if EXPERT
1480 Enable the x86 architectural RDRAND instruction
1481 (Intel Bull Mountain technology) to generate random numbers.
1482 If supported, this is a high bandwidth, cryptographically
1483 secure hardware random number generator.
1486 bool "EFI runtime service support"
1489 This enables the kernel to use EFI runtime services that are
1490 available (such as the EFI variable services).
1492 This option is only useful on systems that have EFI firmware.
1493 In addition, you should use the latest ELILO loader available
1494 at <http://elilo.sourceforge.net> in order to take advantage
1495 of EFI runtime services. However, even with this option, the
1496 resultant kernel should continue to boot on existing non-EFI
1500 bool "EFI stub support"
1503 This kernel feature allows a bzImage to be loaded directly
1504 by EFI firmware without the use of a bootloader.
1506 See Documentation/x86/efi-stub.txt for more information.
1510 prompt "Enable seccomp to safely compute untrusted bytecode"
1512 This kernel feature is useful for number crunching applications
1513 that may need to compute untrusted bytecode during their
1514 execution. By using pipes or other transports made available to
1515 the process as file descriptors supporting the read/write
1516 syscalls, it's possible to isolate those applications in
1517 their own address space using seccomp. Once seccomp is
1518 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1519 and the task is only allowed to execute a few safe syscalls
1520 defined by each seccomp mode.
1522 If unsure, say Y. Only embedded should say N here.
1524 config CC_STACKPROTECTOR
1525 bool "Enable -fstack-protector buffer overflow detection"
1527 This option turns on the -fstack-protector GCC feature. This
1528 feature puts, at the beginning of functions, a canary value on
1529 the stack just before the return address, and validates
1530 the value just before actually returning. Stack based buffer
1531 overflows (that need to overwrite this return address) now also
1532 overwrite the canary, which gets detected and the attack is then
1533 neutralized via a kernel panic.
1535 This feature requires gcc version 4.2 or above, or a distribution
1536 gcc with the feature backported. Older versions are automatically
1537 detected and for those versions, this configuration option is
1538 ignored. (and a warning is printed during bootup)
1540 source kernel/Kconfig.hz
1543 bool "kexec system call"
1545 kexec is a system call that implements the ability to shutdown your
1546 current kernel, and to start another kernel. It is like a reboot
1547 but it is independent of the system firmware. And like a reboot
1548 you can start any kernel with it, not just Linux.
1550 The name comes from the similarity to the exec system call.
1552 It is an ongoing process to be certain the hardware in a machine
1553 is properly shutdown, so do not be surprised if this code does not
1554 initially work for you. It may help to enable device hotplugging
1555 support. As of this writing the exact hardware interface is
1556 strongly in flux, so no good recommendation can be made.
1559 bool "kernel crash dumps"
1560 depends on X86_64 || (X86_32 && HIGHMEM)
1562 Generate crash dump after being started by kexec.
1563 This should be normally only set in special crash dump kernels
1564 which are loaded in the main kernel with kexec-tools into
1565 a specially reserved region and then later executed after
1566 a crash by kdump/kexec. The crash dump kernel must be compiled
1567 to a memory address not used by the main kernel or BIOS using
1568 PHYSICAL_START, or it must be built as a relocatable image
1569 (CONFIG_RELOCATABLE=y).
1570 For more details see Documentation/kdump/kdump.txt
1573 bool "kexec jump (EXPERIMENTAL)"
1574 depends on EXPERIMENTAL
1575 depends on KEXEC && HIBERNATION
1577 Jump between original kernel and kexeced kernel and invoke
1578 code in physical address mode via KEXEC
1580 config PHYSICAL_START
1581 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1584 This gives the physical address where the kernel is loaded.
1586 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1587 bzImage will decompress itself to above physical address and
1588 run from there. Otherwise, bzImage will run from the address where
1589 it has been loaded by the boot loader and will ignore above physical
1592 In normal kdump cases one does not have to set/change this option
1593 as now bzImage can be compiled as a completely relocatable image
1594 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1595 address. This option is mainly useful for the folks who don't want
1596 to use a bzImage for capturing the crash dump and want to use a
1597 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1598 to be specifically compiled to run from a specific memory area
1599 (normally a reserved region) and this option comes handy.
1601 So if you are using bzImage for capturing the crash dump,
1602 leave the value here unchanged to 0x1000000 and set
1603 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1604 for capturing the crash dump change this value to start of
1605 the reserved region. In other words, it can be set based on
1606 the "X" value as specified in the "crashkernel=YM@XM"
1607 command line boot parameter passed to the panic-ed
1608 kernel. Please take a look at Documentation/kdump/kdump.txt
1609 for more details about crash dumps.
1611 Usage of bzImage for capturing the crash dump is recommended as
1612 one does not have to build two kernels. Same kernel can be used
1613 as production kernel and capture kernel. Above option should have
1614 gone away after relocatable bzImage support is introduced. But it
1615 is present because there are users out there who continue to use
1616 vmlinux for dump capture. This option should go away down the
1619 Don't change this unless you know what you are doing.
1622 bool "Build a relocatable kernel"
1625 This builds a kernel image that retains relocation information
1626 so it can be loaded someplace besides the default 1MB.
1627 The relocations tend to make the kernel binary about 10% larger,
1628 but are discarded at runtime.
1630 One use is for the kexec on panic case where the recovery kernel
1631 must live at a different physical address than the primary
1634 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1635 it has been loaded at and the compile time physical address
1636 (CONFIG_PHYSICAL_START) is ignored.
1638 # Relocation on x86-32 needs some additional build support
1639 config X86_NEED_RELOCS
1641 depends on X86_32 && RELOCATABLE
1643 config PHYSICAL_ALIGN
1644 hex "Alignment value to which kernel should be aligned" if X86_32
1646 range 0x2000 0x1000000
1648 This value puts the alignment restrictions on physical address
1649 where kernel is loaded and run from. Kernel is compiled for an
1650 address which meets above alignment restriction.
1652 If bootloader loads the kernel at a non-aligned address and
1653 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1654 address aligned to above value and run from there.
1656 If bootloader loads the kernel at a non-aligned address and
1657 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1658 load address and decompress itself to the address it has been
1659 compiled for and run from there. The address for which kernel is
1660 compiled already meets above alignment restrictions. Hence the
1661 end result is that kernel runs from a physical address meeting
1662 above alignment restrictions.
1664 Don't change this unless you know what you are doing.
1667 bool "Support for hot-pluggable CPUs"
1668 depends on SMP && HOTPLUG
1670 Say Y here to allow turning CPUs off and on. CPUs can be
1671 controlled through /sys/devices/system/cpu.
1672 ( Note: power management support will enable this option
1673 automatically on SMP systems. )
1674 Say N if you want to disable CPU hotplug.
1678 prompt "Compat VDSO support"
1679 depends on X86_32 || IA32_EMULATION
1681 Map the 32-bit VDSO to the predictable old-style address too.
1683 Say N here if you are running a sufficiently recent glibc
1684 version (2.3.3 or later), to remove the high-mapped
1685 VDSO mapping and to exclusively use the randomized VDSO.
1690 bool "Built-in kernel command line"
1692 Allow for specifying boot arguments to the kernel at
1693 build time. On some systems (e.g. embedded ones), it is
1694 necessary or convenient to provide some or all of the
1695 kernel boot arguments with the kernel itself (that is,
1696 to not rely on the boot loader to provide them.)
1698 To compile command line arguments into the kernel,
1699 set this option to 'Y', then fill in the
1700 the boot arguments in CONFIG_CMDLINE.
1702 Systems with fully functional boot loaders (i.e. non-embedded)
1703 should leave this option set to 'N'.
1706 string "Built-in kernel command string"
1707 depends on CMDLINE_BOOL
1710 Enter arguments here that should be compiled into the kernel
1711 image and used at boot time. If the boot loader provides a
1712 command line at boot time, it is appended to this string to
1713 form the full kernel command line, when the system boots.
1715 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1716 change this behavior.
1718 In most cases, the command line (whether built-in or provided
1719 by the boot loader) should specify the device for the root
1722 config CMDLINE_OVERRIDE
1723 bool "Built-in command line overrides boot loader arguments"
1724 depends on CMDLINE_BOOL
1726 Set this option to 'Y' to have the kernel ignore the boot loader
1727 command line, and use ONLY the built-in command line.
1729 This is used to work around broken boot loaders. This should
1730 be set to 'N' under normal conditions.
1734 config ARCH_ENABLE_MEMORY_HOTPLUG
1736 depends on X86_64 || (X86_32 && HIGHMEM)
1738 config ARCH_ENABLE_MEMORY_HOTREMOVE
1740 depends on MEMORY_HOTPLUG
1742 config USE_PERCPU_NUMA_NODE_ID
1746 menu "Power management and ACPI options"
1748 config ARCH_HIBERNATION_HEADER
1750 depends on X86_64 && HIBERNATION
1752 source "kernel/power/Kconfig"
1754 source "drivers/acpi/Kconfig"
1756 source "drivers/sfi/Kconfig"
1763 tristate "APM (Advanced Power Management) BIOS support"
1764 depends on X86_32 && PM_SLEEP
1766 APM is a BIOS specification for saving power using several different
1767 techniques. This is mostly useful for battery powered laptops with
1768 APM compliant BIOSes. If you say Y here, the system time will be
1769 reset after a RESUME operation, the /proc/apm device will provide
1770 battery status information, and user-space programs will receive
1771 notification of APM "events" (e.g. battery status change).
1773 If you select "Y" here, you can disable actual use of the APM
1774 BIOS by passing the "apm=off" option to the kernel at boot time.
1776 Note that the APM support is almost completely disabled for
1777 machines with more than one CPU.
1779 In order to use APM, you will need supporting software. For location
1780 and more information, read <file:Documentation/power/apm-acpi.txt>
1781 and the Battery Powered Linux mini-HOWTO, available from
1782 <http://www.tldp.org/docs.html#howto>.
1784 This driver does not spin down disk drives (see the hdparm(8)
1785 manpage ("man 8 hdparm") for that), and it doesn't turn off
1786 VESA-compliant "green" monitors.
1788 This driver does not support the TI 4000M TravelMate and the ACER
1789 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1790 desktop machines also don't have compliant BIOSes, and this driver
1791 may cause those machines to panic during the boot phase.
1793 Generally, if you don't have a battery in your machine, there isn't
1794 much point in using this driver and you should say N. If you get
1795 random kernel OOPSes or reboots that don't seem to be related to
1796 anything, try disabling/enabling this option (or disabling/enabling
1799 Some other things you should try when experiencing seemingly random,
1802 1) make sure that you have enough swap space and that it is
1804 2) pass the "no-hlt" option to the kernel
1805 3) switch on floating point emulation in the kernel and pass
1806 the "no387" option to the kernel
1807 4) pass the "floppy=nodma" option to the kernel
1808 5) pass the "mem=4M" option to the kernel (thereby disabling
1809 all but the first 4 MB of RAM)
1810 6) make sure that the CPU is not over clocked.
1811 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1812 8) disable the cache from your BIOS settings
1813 9) install a fan for the video card or exchange video RAM
1814 10) install a better fan for the CPU
1815 11) exchange RAM chips
1816 12) exchange the motherboard.
1818 To compile this driver as a module, choose M here: the
1819 module will be called apm.
1823 config APM_IGNORE_USER_SUSPEND
1824 bool "Ignore USER SUSPEND"
1826 This option will ignore USER SUSPEND requests. On machines with a
1827 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1828 series notebooks, it is necessary to say Y because of a BIOS bug.
1830 config APM_DO_ENABLE
1831 bool "Enable PM at boot time"
1833 Enable APM features at boot time. From page 36 of the APM BIOS
1834 specification: "When disabled, the APM BIOS does not automatically
1835 power manage devices, enter the Standby State, enter the Suspend
1836 State, or take power saving steps in response to CPU Idle calls."
1837 This driver will make CPU Idle calls when Linux is idle (unless this
1838 feature is turned off -- see "Do CPU IDLE calls", below). This
1839 should always save battery power, but more complicated APM features
1840 will be dependent on your BIOS implementation. You may need to turn
1841 this option off if your computer hangs at boot time when using APM
1842 support, or if it beeps continuously instead of suspending. Turn
1843 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1844 T400CDT. This is off by default since most machines do fine without
1848 bool "Make CPU Idle calls when idle"
1850 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1851 On some machines, this can activate improved power savings, such as
1852 a slowed CPU clock rate, when the machine is idle. These idle calls
1853 are made after the idle loop has run for some length of time (e.g.,
1854 333 mS). On some machines, this will cause a hang at boot time or
1855 whenever the CPU becomes idle. (On machines with more than one CPU,
1856 this option does nothing.)
1858 config APM_DISPLAY_BLANK
1859 bool "Enable console blanking using APM"
1861 Enable console blanking using the APM. Some laptops can use this to
1862 turn off the LCD backlight when the screen blanker of the Linux
1863 virtual console blanks the screen. Note that this is only used by
1864 the virtual console screen blanker, and won't turn off the backlight
1865 when using the X Window system. This also doesn't have anything to
1866 do with your VESA-compliant power-saving monitor. Further, this
1867 option doesn't work for all laptops -- it might not turn off your
1868 backlight at all, or it might print a lot of errors to the console,
1869 especially if you are using gpm.
1871 config APM_ALLOW_INTS
1872 bool "Allow interrupts during APM BIOS calls"
1874 Normally we disable external interrupts while we are making calls to
1875 the APM BIOS as a measure to lessen the effects of a badly behaving
1876 BIOS implementation. The BIOS should reenable interrupts if it
1877 needs to. Unfortunately, some BIOSes do not -- especially those in
1878 many of the newer IBM Thinkpads. If you experience hangs when you
1879 suspend, try setting this to Y. Otherwise, say N.
1883 source "drivers/cpufreq/Kconfig"
1885 source "drivers/cpuidle/Kconfig"
1887 source "drivers/idle/Kconfig"
1892 menu "Bus options (PCI etc.)"
1897 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1899 Find out whether you have a PCI motherboard. PCI is the name of a
1900 bus system, i.e. the way the CPU talks to the other stuff inside
1901 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1902 VESA. If you have PCI, say Y, otherwise N.
1905 prompt "PCI access mode"
1906 depends on X86_32 && PCI
1909 On PCI systems, the BIOS can be used to detect the PCI devices and
1910 determine their configuration. However, some old PCI motherboards
1911 have BIOS bugs and may crash if this is done. Also, some embedded
1912 PCI-based systems don't have any BIOS at all. Linux can also try to
1913 detect the PCI hardware directly without using the BIOS.
1915 With this option, you can specify how Linux should detect the
1916 PCI devices. If you choose "BIOS", the BIOS will be used,
1917 if you choose "Direct", the BIOS won't be used, and if you
1918 choose "MMConfig", then PCI Express MMCONFIG will be used.
1919 If you choose "Any", the kernel will try MMCONFIG, then the
1920 direct access method and falls back to the BIOS if that doesn't
1921 work. If unsure, go with the default, which is "Any".
1926 config PCI_GOMMCONFIG
1943 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1945 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1948 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1952 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1956 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1960 depends on PCI && XEN
1968 bool "Support mmconfig PCI config space access"
1969 depends on X86_64 && PCI && ACPI
1971 config PCI_CNB20LE_QUIRK
1972 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1974 depends on PCI && EXPERIMENTAL
1976 Read the PCI windows out of the CNB20LE host bridge. This allows
1977 PCI hotplug to work on systems with the CNB20LE chipset which do
1980 There's no public spec for this chipset, and this functionality
1981 is known to be incomplete.
1983 You should say N unless you know you need this.
1985 source "drivers/pci/pcie/Kconfig"
1987 source "drivers/pci/Kconfig"
1989 # x86_64 have no ISA slots, but can have ISA-style DMA.
1991 bool "ISA-style DMA support" if (X86_64 && EXPERT)
1994 Enables ISA-style DMA support for devices requiring such controllers.
2002 Find out whether you have ISA slots on your motherboard. ISA is the
2003 name of a bus system, i.e. the way the CPU talks to the other stuff
2004 inside your box. Other bus systems are PCI, EISA, MicroChannel
2005 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2006 newer boards don't support it. If you have ISA, say Y, otherwise N.
2012 The Extended Industry Standard Architecture (EISA) bus was
2013 developed as an open alternative to the IBM MicroChannel bus.
2015 The EISA bus provided some of the features of the IBM MicroChannel
2016 bus while maintaining backward compatibility with cards made for
2017 the older ISA bus. The EISA bus saw limited use between 1988 and
2018 1995 when it was made obsolete by the PCI bus.
2020 Say Y here if you are building a kernel for an EISA-based machine.
2024 source "drivers/eisa/Kconfig"
2027 tristate "NatSemi SCx200 support"
2029 This provides basic support for National Semiconductor's
2030 (now AMD's) Geode processors. The driver probes for the
2031 PCI-IDs of several on-chip devices, so its a good dependency
2032 for other scx200_* drivers.
2034 If compiled as a module, the driver is named scx200.
2036 config SCx200HR_TIMER
2037 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2041 This driver provides a clocksource built upon the on-chip
2042 27MHz high-resolution timer. Its also a workaround for
2043 NSC Geode SC-1100's buggy TSC, which loses time when the
2044 processor goes idle (as is done by the scheduler). The
2045 other workaround is idle=poll boot option.
2048 bool "One Laptop Per Child support"
2055 Add support for detecting the unique features of the OLPC
2059 bool "OLPC XO-1 Power Management"
2060 depends on OLPC && MFD_CS5535 && PM_SLEEP
2063 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2066 bool "OLPC XO-1 Real Time Clock"
2067 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2069 Add support for the XO-1 real time clock, which can be used as a
2070 programmable wakeup source.
2073 bool "OLPC XO-1 SCI extras"
2074 depends on OLPC && OLPC_XO1_PM
2079 Add support for SCI-based features of the OLPC XO-1 laptop:
2080 - EC-driven system wakeups
2084 - AC adapter status updates
2085 - Battery status updates
2087 config OLPC_XO15_SCI
2088 bool "OLPC XO-1.5 SCI extras"
2089 depends on OLPC && ACPI
2092 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2093 - EC-driven system wakeups
2094 - AC adapter status updates
2095 - Battery status updates
2098 bool "PCEngines ALIX System Support (LED setup)"
2101 This option enables system support for the PCEngines ALIX.
2102 At present this just sets up LEDs for GPIO control on
2103 ALIX2/3/6 boards. However, other system specific setup should
2106 Note: You must still enable the drivers for GPIO and LED support
2107 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2109 Note: You have to set alix.force=1 for boards with Award BIOS.
2112 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2115 This option enables system support for the Soekris Engineering net5501.
2118 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2122 This option enables system support for the Traverse Technologies GEOS.
2128 depends on CPU_SUP_AMD && PCI
2130 source "drivers/pcmcia/Kconfig"
2132 source "drivers/pci/hotplug/Kconfig"
2135 bool "RapidIO support"
2139 If you say Y here, the kernel will include drivers and
2140 infrastructure code to support RapidIO interconnect devices.
2142 source "drivers/rapidio/Kconfig"
2147 menu "Executable file formats / Emulations"
2149 source "fs/Kconfig.binfmt"
2151 config IA32_EMULATION
2152 bool "IA32 Emulation"
2154 select COMPAT_BINFMT_ELF
2156 Include code to run legacy 32-bit programs under a
2157 64-bit kernel. You should likely turn this on, unless you're
2158 100% sure that you don't have any 32-bit programs left.
2161 tristate "IA32 a.out support"
2162 depends on IA32_EMULATION
2164 Support old a.out binaries in the 32bit emulation.
2167 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2168 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2170 Include code to run binaries for the x32 native 32-bit ABI
2171 for 64-bit processors. An x32 process gets access to the
2172 full 64-bit register file and wide data path while leaving
2173 pointers at 32 bits for smaller memory footprint.
2175 You will need a recent binutils (2.22 or later) with
2176 elf32_x86_64 support enabled to compile a kernel with this
2181 depends on IA32_EMULATION || X86_X32
2182 select ARCH_WANT_OLD_COMPAT_IPC
2184 config COMPAT_FOR_U64_ALIGNMENT
2188 config SYSVIPC_COMPAT
2190 depends on COMPAT && SYSVIPC
2194 depends on COMPAT && KEYS
2200 config HAVE_ATOMIC_IOMAP
2204 config HAVE_TEXT_POKE_SMP
2206 select STOP_MACHINE if SMP
2208 config X86_DEV_DMA_OPS
2210 depends on X86_64 || STA2X11
2212 config X86_DMA_REMAP
2216 source "net/Kconfig"
2218 source "drivers/Kconfig"
2220 source "drivers/firmware/Kconfig"
2224 source "arch/x86/Kconfig.debug"
2226 source "security/Kconfig"
2228 source "crypto/Kconfig"
2230 source "arch/x86/kvm/Kconfig"
2232 source "lib/Kconfig"